This latest addition to the 'Underworld' series opens six months after the events of the second movie, Underworld: Evolution. The vampire Selene is captured by humans during "The Purge," a massive crusade of war to exterminate vampires and lycans after mankind learns of their existence. Humans call Lycans "Non-Humans" and Vampires are called "The infected."12 years later, it is revealed that human governments all over the world had committed genocides to vampires and lycans, killing everything. Surviving populations were reduced to being scavengers and guerrillas. 90% of the vampire race was annihilated. Selene is freed from cryogenic suspension and escapes the medical corporation Antigen. The corporation is trying to make an antidote for the virus that creates vampires and lycans. Selene starts to have strange visions after her escape, which she follows, believing them to be linked to her lover, the vampire-lycan hybrid Michael Corvin. The visions lead her into a building where she runs into David, a fellow vampire.While talking to David, Selene has another vision. Following the vision, she discovers not Michael, but a young girl called only "Subject 2," also known as Eve. Later revealed to be a hybrid and Selene and Michael's daughter. David, noting that Eve (Subject 2) has been injured by the lycans and is somehow not healing, takes them to his coven. David's father, Thomas, does not welcome Selene and Eve, stunning Selene with the news that Michael died twelve years ago and that Selene was the cause for the destruction of the vampire race. Upon being given some vampire blood, Eve heals extremely quickly.Dr. Jacob Lane, director of Antigen, is revealed to be a lycan alongside his son, Quint. The "antidote" the corporation has been working on for many years is actually to make lycans immune to the deadly effects of silver and to enhance their physical abilities. Eve's hybrid genetic code is required to achieve this, so Lane sends Quint with other lycans to the vampire coven to recapture her.Meanwhile, expecting a human attacks at any moment, David tries to rally the vampires resistances to fight back, while his father orders everyone to evacuate and hide. Most of the vampires stay, and arm themselves heavily. Unexpectedly, lycans arrived in large numbers instead, and numerous vampires are slaughtered, a huge blow to the coven. Selene encounters a gigantic "super lycan", who is later revealed to be Quint, his body changed by injections using Eve's blood. Selene is knocked unconscious under a pile of rubble, Eve is turned over to the lycans by Thomas in exchange for their departure, and David is mortally wounded during the battle. Selene decides to save Eve but first revives David using her immortal blood, given to her by Alexander Corvinus in Evolution.Able to survive in sunlight, Selene enlists the help of Detective Sebastian, a human who tried to investigate Antigen earlier in the film. Sebastian agrees to help save Eve, admitting he was married to a nurse who was bitten at work and became a vampire, until she was killed by authorities during the Purge; they forced her to out into the day, into direct daylight, and she was burned to death.Selene destroys part of Antigen's headquarters using explosives and silver gas, forcing Dr. Lane to move Eve out of the building to perform an operation to create more of the antidote. Selene escapes from the lycans in the building. (Antigen is nearly entirely staffed by lycans) In the process, she finds Michael cryogenically frozen in a laboratory. She shoots his cell to let him out. Escaping in a van, Dr. Lane is intercepted by Sebastian and then by Selene, who causes the van to crash. Quint arrives, transforms into his super lycan form, and fights Selene.Eve awakens on her stretcher, frees herself from the van, and engages Dr. Lane in a fight, who has injected himself with the super lycan formula used on Quint. Sebastian and the revived David aid Eve in her fight until she kills Dr. Lane by ripping his throat out.Meanwhile, Quint corners Selene in a small cement guardroom but is forced to revert to his human form to get to her, only for Selene to shove an activated silver-based grenade into Quint's body. He heals instantly, trapping the grenade inside. Panicking, he half-changes back to lycan form, but it is too late, and he explodes.Selene goes to find Michael but finds an empty cryogenic cell with Eve sharing his vision and learns he is on the roof. Selene, Eve, and David run to the roof only to find Michael has gone. Selene narrates, concluding that she will find Michael and take back the world from the humans and lycans, so the vampires can rebuild themselves as the humans declared war.